1. Field of Invention
The present invention relates to a semi-conductive device. More particularly, the present invention relates to a non-volatile memory and a fabricating method thereof.
1. Description of Related Art
Among the non-volatile memories, the flash memory has become one of the most researched products in the industry due to the time-saving operation mode and the cost-saving advantage. Wherein the commonly used flash arrays include the NOR type array structure and NAND type array structure. The structure of flash memory with the NAND type array is to have the memory cells connected in series. The integration and the spatial utilization of flash memory with NAND type array are better than the flash memory with NOR type array. Therefore, the flash memory structure of the NAND type array has been widely used in various electronic products.
In the current market, the NAND type array flash memory mainly has a floating gate and a control gate, and the fabricating process usually requires more than two masks to define these two gates. In other words, more than two lithographing and etching processes are required to complete the fabrication. However, in the semiconductor device fabricating process, the lithographic etching process is the most complicated and most expensive part. Therefore, more lithographic etching process (more masks) usually leads to increased cost and the time consumption during the fabricating process.
In addition, since the floating gate and control gate are formed by etching the conductive layer directly, micro-bridges are likely formed between adjacent conductive layers, which consequently causes short-circuit. This problem may become more serious as the line width reduces.